# Fundie Probability: Even Worse Math than Swinburne

I recently got a real prize of a link from one of my readers. He’d enjoyed the [Swinburne][swinburne] article, and had encoutered this monstrosity; an alleged [probability of christianity][prob] argument *significantly worse* than Swinburne.
[swinburne]: http://goodmath.blogspot.com/2006/04/mind-numbingly-stupid-math.html “My shredding of Swinburne”
[prob]: http://www.biblebelievers.org.au/radio034.htm “Mathematical Probability that Jesus is the Christ”
The difference between Swinburne and this bozo (who’s name I can’t locate on the site) is that at least Swinburne made *some* attempt to use some math to justify his position. It may have been sloppy as hell – but at least he *did* go through the effort of using actual Bayesian methods. I think that he did an *appallingly* bad job of it; but at least there was something there.
Our new friend doesn’t even bother to do that.
Here’s a very typical example of his “argument”:
>The reason why prophecy is an indication of the divine authorship of the Scriptures, and hence a testimony to the trustworthiness of the Message of the Scriptures, is because of the minute probability of fulfillment.
>
>Anyone can make predictions. Having those prophecies fulfilled is vastly different. In fact, the more statements made about the future, and the more the detail, then the less likely the precise fulfillment will be.
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>For example, what’s the likelihood of a person predicting today the exact city in which the birth of a future leader would take place, well into the 21st century? This is indeed what the prophet Micah did 700 years before the Messiah. Further, what is the likelihood of predicting the precise manner of death that a new, unknown religious leader would experience, a thousand years from now – a manner of death presently unknown, and to remain unknown for hundreds of years? Yet, this is what David did in 1000 B.C.
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>Again, what is the likelihood of predicting the specific date of the appearance of some great future leader, hundreds of years in advance? This is what Daniel did, 530 years before Christ.
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>If one were to conceive 50 specific prophecies about a person in the future, whom one would never meet, just what’s the likelihood that this person will fulfill all 50 of the predictions? How much less would this likelihood be if 25 of these predictions were about what other people would do to him, and were completely beyond his control?
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>For example, how does someone “arrange” to be born in a specific family?
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>How does one “arrange” to be born in a specified city, in which their parents don’t actually live? How does one “arrange” their own death – and specifically by crucifixion, with two others, and then “arrange” to have their executioners gamble for His clothing (John 16:19; Psalms 22:18)? How does one “arrange” to be betrayed in advance? How does one “arrange” to have the executioners carry out the regular practice of breaking the legs of the two victims on either side, but not their own? Finally, how does one “arrange” to be God? How does one escape from a grave and appear to people after having been killed?
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>Indeed, it may be possible for someone to fake one or two of the Messianic prophecies, but it would be impossible for any one person to arrange and fulfill all of these prophecies.
So the basic method is. Assert that there were prophecies that unambiguously identified a specific event. Further, assert that those prophecies were fulfilled. Now, ask, what’s the probability of all of those prophecies coming true?
The arguments that he presents range from the vague to the silly. In the vague cases, he makes a classic mathematical mistake: switching between a priori and a posteori probabilities. In general, probability calculations are done a priori: “I *don’t know* what specific situation I’m going to apply my calculations to, so when I set the probabilities, I do it without any specific knowledge of a desired outcome”. But he does it a posteori: “Since this description of an event *clearly references* this specific incident, I’m going to set the probabilities using my knowledge of the outcome”.
For example, he asserts things like prophecies naming a specific city in which his alleged messiah would be borne. Of course, the specific prophesy that supposedly makes this claim is not specified. And if you go to other places that babble about the various prophecies about the messiah, you find that none of them are actually *specific*. That is, they all talk in very vague and symbolic terms, and *a posteori* interpretations of those can say that they identify a specific place associated with Jesus; but if you were to read them with an open mind, without any idea of a set of events that you were trying to link them to, you almost certainly would not have demanded that they describe a single, specific location. If they could describe 20 locations, then your probability calculations would need to include the probability for each of those possibilities; if you use the a posteori perspective to narrow it down to one, you’re making invalid use of hindsight to skew the numbers.
Even worse than just using the alleged fulfillment of vague prophecies, he makes an even worse kind of a posteori error: numerous citations of prophecies from the *new* testament: a set of books written *after* the events that were supposedly prophesized – as in the citation of the book of John in the quoted section above. We’re supposed to take the fulfillment of a prophecy that wasn’t written down until *after* the event, and act surprised that there’s exactly one supposedly historical event that matches that prophesy.
Ooh, I’m surprised. A bunch of guys who were trying to convince the world that Jesus was the messiah wrote down prophesies *after the fact* in a way that only Jesus could possibly have fulfilled. Adding *that* to an alleged probability calculation to reduce the probability of anyone but Jesus fulfilling all of the prophecies isn’t even bad math. It’s just plain old lying.
In the category of just plain silly, I absolutely *love* the quote where he’s talking about how hard it would be for anyone else to fulfill these alleged prophecies: “how does one “arrange” to be God?”. Yeah, one of the statements that he supposedly calculuates a probability for is “being God”.
What’s the probability of being God? I’d really like to know. Do I have any real chance of fulling it?
Alas, I can’t tell, Because despite insisting that there are 456 different prophesies that Jesus supposedly fulfilled, and that each of those is factored into the calculuation, he doesn’t tell us how any of those individual probabilities were calculated – for example, he says the probability of an alleged messiah being born in Bethlehem was one in 2.8×105. Where’d that number come from? We don’t know.
And for most of the alleged events that were fulfilled prophesies, he doesn’t even give us that much information.
For example, he says that the odds of fulfilling 48 prophesies – he doesn’t say which 48 – is 1 in 10157. He just asserts that. And then goes off into a classic “big numbers” babble about how terribly unimaginably large that number is. He even goes so far as to pull out one of those bullshit “anything less likely than X is impossible”. (I’m actually playing a game of spider solitaire in the background as a write this; which means that I’m doing something absolutely impossible!)
He’s even got a ripoff of the PSICOP challenge:
>But, of course, there are many more than eight prophecies. In another calculation, Stoner used 48 prophecies (Idem, 109) (even though he could have used Edersheim’s 456), and arrived at the extremely conservative estimate that the probability of 48 prophecies being fulfilled in one person is the incredible number 10^157. In fact, if anybody can find someone, living or dead, other than Jesus, who can fulfill only half of the predictions concerning the Messiah given in the book “Messiah in Both Testaments” by Fred J. Meldau, the Christian Victory Publishing Company is ready to give a ONE thousand dollar reward! As apologist Josh McDowell says, “There are a lot of men in the universities that could use some extra cash!” (Josh McDowell, Evidence that Demands a Verdict, California: Campus Crusade for Christ, 175).
The catch of course is that you need to fulfill the prophesies *in exactly the way that these fundies interpret them* – in other words, starting from the assumption that Jesus fulfilled them, and that the prophecies specifically point at exactly the events of the life of Jesus.
I can actually save the authors a lot of trouble. The probability of anyone else fulfilling these prophesies *is zero*. Because they’re interpreted a posteori as the specific events from the life of Jesus, the odds of it being Jesus who fulfilled them is exactly 100%, and the odds of anyone else doing it are exactly 0%.
Course, if you put it that way, suddenly it doesn’t sound so impressive, even to the bunch of idiots who’d accept this argument to begin with.